1. Field of the Invention
This invention relates to a seam welded steel pipe which, generally to serve as a fuel pipe in an automobile or other internal combustion engine using gasoline, is provided on the inner wall surface thereof with a coating for preventing gasoline from oxidation and, further to serve concurrently as a feed pipe for various gas or liquid, is vested on the inner surface thereof with corrosionproofness and to a method for the production of the steel pipe.
2. Description of the Prior Art
Heretofore, the seam welded steel pipe of this kind has been produced by a process which comprises applying a Cu coating (12) on the inner surface of a seam welded steel pipe (11) by plating and then coating the surface of the Cu coating uniformly with a layer of Sn or a Sn alloy (13) by hot dipping throughout the entire inner surface embracing the neighborhood of a bead part (14).
In the conventional seam welded steel pipe and the method for the production thereof described above, though the aforementioned layer of Sn or Sn alloy (13) formed by hot dipping and allowed to embrace the bead part (14) curbs the formation of so-called sour gasoline to some extent by preventing the steel pipe from cauisng oxidation of gasoline, this prevention of the oxidation of gasoline cannot be attained completely because of the formation of pinholes in consequence of the deposition of layer by hot dipping. Further this formation of pinholes renders the formation of the layer (13) with tolerable uniformity by hot dipping extremely difficult and keeps the impartation of corrosionproofness from reaching a level of satisfaction. Moreover, the treatment of hot dipping itself is such as to impose limits on the diameter and length of the seam welded steel pipe to be obtained and seriously complicate the aforementioned process of treatment.